Apparatus for burning coal dust



June 10, 1930. A. HASSELBACH ET AL APPARATUS FOR BURNING COAL DUST Filed March 23. 1927 Fritz Luther $3M atte anew Patented June 10, 193i) UNITED STATES PATENT OFFICE,

A LEXANDER HASSELBAGH AND FRITZ LUTHER, F DESSAU', (mam, A SIGNOBS TO G. POLYSIUS, A. F131 01' DESSAU,,GEBIANY.

APPARATUS FOR BURNING GOAL DUST Application filed March 23, 1927, Serial 170. 177,580, and in Germany December '18, 1986.

This invention relates to the burning ofcoal dust, or other finely sub-divided solid fuel and is particularly applicable for use with rotary kilns or the like which are em- 5 ployed for burning, roasting or clinkering cement or similar material. Coal dust and other finely sub-divided solid fuel contains considerable quantities of vola-' tile matter and when delivered through an ordinary nozzle consisting of a simple tube, the solid fuel or the volatile portion thereof often ignites and burns within the nozzle, 1f the latter be heated. This is objectionable and occurs particularly with rotary kilns for burning material of all lands, where the nozzle projects into the kiln and the burned material radiates intense heat to the nozzle.

This is' avoided by the present invention. In carrying out the invention, one part of the combustion supporting air is used for delivering the coal dust through the nozzle and another part of the combustion supporting air is delivered through an exterior pipe comprising a closed cooling jacket around the coal dust nozzle so as to protect the latter from the high heat in the kiln.

As a further feature of the invention, the admission nozzle is preferably formed of sections adapted to telescope so as to permit adjustment of the nozzle in a longitudinal direction whereby the desired heating or burnin may best be accomplished in the'kiln.

n the accompanying drawing, there are illustrated merely as examples two forms of apparatus embodying the invention and which may be used for carrying out the process.

In these drawings:

Fig. l-is a longitudinal section through one foam of nozzle and the cooperating parts; an r f Fig. 2 is a similar section showing another orm.

In Fig. 1 a blower-a delivers a part of the combustion su porting air through an air nozzle 6 into t e coal dust nozzle or admisthelr sion pipe (1. The coal dust is admitted to the piped at a point adjacent to the air nozzle 6 as for instance, through a pipe 0. The coal dust is delivered into lnln from'the free end of the pipe d. and there-is burned. Ordinarily the pipe projects some distance into the kiln and the latter is mounted for rotation.

Around the dust admission pipe :1 thereis placed a second pipe f which is also connected to the outlet of the blower around the air nozzle 6 so that it also-receives air from the blower. The pipe f extends lengthwise of an encloses the pipe (1 and terminates within the kiln adjacent to the end of the pipe d so that the air delivered through the outer pipe cools and protects thein'nerpipe and prevents the fuel from catching'fire within the inner pipe. The amount of air delivered through the pipe (1 is insuflicient for supporting complete combustion and thus the air delivered from the outer pipe serves for not only cooling the inner pipe, but for the additional air required for complete combustion.

In order to permit an adjustment or a removal of the dust nozzle and delivery pipe, in a longitudinal direction, the pipes d and f may each be made of two or more telescoping sections. The sections of the pipes which project into the kiln may be guided or supported independently of the other sections of the pipes in any suitable manner as for instance by rollers I; mounted on one or more rails 21.

It is not necessary that the sections of the outer pipe telescope as these sections may be connected by means of a hose 9, as shown in Fig. 2, or by any other equivalent mechanism.. Means may be provided for regulating the relative amounts of air delivered through the inner and outer pipes. I have shown such a regulating. device in the form ofavalvekinthehose.'

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

.1. In combination a combustion chamber,

a blower, a pair of concentric pipes having 96.

I ve inlet ends connected to the outlet 0 the blower and their outlet ends projecting into said chamber, an injector nozzle inthe inner pipe at the blower outlet, and means for delivering solid fuel in finely '100- subdivided condition to the delivery end of said nozzle, whereby a mixture of air and fuel is delivered to the combustion chamber through the inner pipe, and the air delivered through the outer pipe serves to protect said mixture from the heat of said combustion chamber while said mixture is in transit in the inner pipe, and also serves to furnish the additional air required for combustion of the fuel upon the delivery of the mixture to the chamber.

2. In combination a combustion chamber, a rotary blower having an outlet, a pair of concentric pipes. connected to said outlet, the 1 inner of said pipes having an injector nozzle at the inlet end thereof, a pipe for delivering solid fuel in finely subdivided condition radially through the outer pipe into the inner pipe ata point adjacent to the end of said an nozzle, means for regulating the supply of air delivered through the outer pipe, and means for adjusting said pipes simultaneously axially in respect to the combustion chamber.

. a Signed at Leipzig, Germany, this twentyfifth day of February, 1927.

ALEXANDER HASSELBACH.

FRITZ LUTHER. 

